Soul artist, try starting with something simpler. Make a new book file and add just a couple of the chapters and see if you get the same result. I stopped using CS5 because it breaks my hyperlinks so I can't say from experience about it hanging when exporting. InDesign creates a file for each open file to open in case the program crashes. That's why it's opening up all the files. So you can save unsaved changes.
How many levels does your TOC have?
If it's just the one for chapter names only make sure INCLUDE INDESIGN TOC is unchecked.
Try with first level chapter breaks on and off to see your results (with the short book)